Spring structure for cushioned seats



y 0- M. F uND 07,054

SPRING STRUCTURE FOR CUSHIONED SEATS Filed Nov. 13, 1936 J? i 6 a? Patented July 9, 1940 UNITED STATES PATENT OFFICE Morris Freund, Cleveland, Ohio, assignor, by direct and mesne assignments, ,of one-half to Jacob Kronheim, Shaker Heights, Ohio, and one-half to John C. Lincoln, Scottsdale, Ariz'.

Application November 13, 1936, Serial No. 110,664

1 Claim.

This invention relates to spring structures for seats of upholstered furniture, cushioned automobile seats, backs or the like, in which a plurality of specifically constructed, flat springs are assembled by attaching the springs to a frame, all as disclosed in my Patent No. 2,047,411, dated July. 14, 1936, and my copending application Serial No. 68,417, filed March 12, 1936. In this type of spring structures the elevated seating portions of the flat springs are yieldingly interconnected by means of a plurality of short helical springs, preferably symmetrically arranged, so as to effect proper equal distribution of tension over all parts of the seating member of the spring structure, and, in addition, the front ends of the seating portions of the springs and the outer sides of the seating portions of the two outer springs are pivotally and slidably connected to an edge wire, all for the purpose of stiffening the springstructure without decreasing its yield and the proper yield of the seating member under load.

However, spring structures of the type described, do not sufficiently resist deformation under heavier loads, particularly, the central portion of the seating member of a spring structure of the type described, yields too readily to heavier loads placed thereon. This is due to the fact that the central portions of the springs and the edge wire are forcibly drawn and bent inwardly so that the stiffening effect of the edge wire and the helical springs, connecting the seating portions of the springs, is materially decreased.

It is the primary object of the present invention to provide a spring structure embodying a plurality of flat springs secured in an elevated position to a, frame and having their seating portions interconnected with each other in the manner referred to above, with means adapted to resist under load lateral inward movement of the seating portions of the fiat springs.

Another object of the invention is to provide a spring structure embodying a plurality of flat springs-secured in elevated position to a frame and having their seating portions interconnected with each other in the manner referred to above, with means adapted to increase the. stiffness of the seating portion under load by bending the central seating portions of the flat springs laterally and outwardly proportionate to the load placed thereon.

A further object of the invention is to provide a spring structure embodying a plurality of flat springs secured in elevated position to a frame and having their seating portions interconnected with each other in the manner referred to above ing certain novel features of construction are clearly set forth in the following specification and the appended claim; and a preferred form of embodiment of the invention is hereinafter shown with reference to the accompanying drawing forming part of the specification.

In the drawing:

Fig. 1 shows a spring structure of a cushioned seat embodying flat springs secured to a frame and interengaged with each other and a spreading device according to the invention.

Fig. 2 is a cross-sectional view through the spring structure disclosed in Fig. 1 showing more clearly the support of the spreading device on the frame and the pivotal connection of the spreading elements with the lateral edges of the seating surface, the section being taken on line 2--2 of Fig. 1.

Fig. 3 is a longitudinal sectional view through the spring structure disclosed in Fig. 1, the section being taken on line 33 of Fig. 1.

Referring now more particularly to the drawing, reference numeral 2 represents a frame of a spring structure 3 for an upholstered piece of furniture or automobile seat. This frame, which embodies a front rail 4, two side rails 5, 5' and a rear rail 6, has seated thereon and secured thereto a plurality of flat, sinuous springs 1 arranged crosswise of the frame 2 and secured to its front and rear rails 4 and 6 respectively. The springs l are made of steel wire and embody each a (a) Central portion 8 having sinuously shaped loops 9 extendedsubstantially horizontally and parallelly to each other so as to form a longitudinally extensible and/or compressible seating portion,

(b) A downwardly and rearwardly inclined front supporting portion l0, seated upon and secured to the front rail 4 by means of a metal strip II, which strip is attached to the rail by nails l2 and having ear portions M for the ends [5 of the front supporting portion l0 and (c) A rearwardly and downwardly extended rear supporting portion I5, the end It of which is secured to the rear rail 8 by means of a metal strip II, which strip is attached to the rail by nails l8 and provided with struck up channels for the finger end portion 2| of the supporting portion I5.

Preferably, front and rear supporting portions I0 and I5 of each spring 1 are integrally formed with the central or seating portion 8, and the sinuous-shaped wire of portion 8 is extended beyond the rear end of said seating portion and bent on a curve downwardly to form the yielding supporting portion I 5'.

The thus formed springs I, which are readily and easily mounted on and/or demounted from the frame 2, support at the front ends of their seating portions 8 the front portion 22 of a substantially U-shaped edge wire 23, which wire is pivotally secured to said springs by means of clips 24. The side portions 25 of this edge wire are shiftably interlocked with the coils 9 of the two outer springs 7, clips 26 being used for this purpose, and the rear ends 21 of the edge wire are at 28 pivotally secured to the rear rail 6 of the frame 2. Finally, the seating portions 8 of springs 1 are yieldingly interconnected with each other by a plurality of short helical springs 29, which springs are symmetrically distributed over the entire seating surface of the spring structure, so as to effect proper transmission of stresses from one spring to the other and produce a substantially balanced seating surface. which can readily be padded and covered with cloth or the like, all as customary in the art.

A spreading device 30 effects lateral spreading of the thus constructed seating surface of the spring structure and prevents inward bending of the seating portions of the springs by a load centrally placed on the seating surface. This spreading deviceembodies a base member or cross bar 3i, preferably made of angle iron and rigidly secured to the side rails 5, 5 midway between the opposite ends thereof by means of screws 32, which crossbar 3| has secured thereto as at 33, 33' rigid lever arms 34, 34 extending upwardly and outwardly and having their upper ends 35, 35' pivotally engaged with the side portions 25 of the edge wire 23 and one of the loops 9 of each of the outer springs I. As the pivotal connections of the upper ends 35, 35 of the lever arms 34 with the edge wire 25 are substantially above the pivotal connections of these arms with the cross bar 3| the lever arms 34 prevent inward bending of the edge wire portions 25 and the seating portions 3 of the springs .I, and, when under heavy load, the seating surface is moved downwardly, these lever arms effect lateral outward bending movements of the edge wire portions 25 and the seating portions 8 of the.springs 1, the short helical springs 29 transmitting the bending movements to the seating portions of the springs and particularly to those portions 01' these seating portions which are located in the central area of the seating surface. The described action of the spreading device 3| effects tensioning of all helical springs and particularly of the springs interconnecting the central areas of the seating portions 8 of the springs I, and thus materially stiffen the resistance of each seating portion of a spring against downward bulging, the increase in resistance being a direct function of the load placed upon the seating surface. A tension spring 36 interconnecting the lever arms 3!, 34' with each other yieldingly resists a too readily downward and spreading movement of these arms.

Having thus described my invention, what I- claim is:

As an article of manufacture and'sale a cushioned seat for automobiles, upholstered furniture and the like comprising a frame, a plurality of springs arranged side by side across said frame, each of said springs embodying an upper, horizontally corrugated seating portion and rearwardly and downwardly extending yielding lever arms of different length at the front and rear ends of said seating portion rigidly connected to said seating portion and attached to said frame for supporting the springs, the lever arm at the front end of the seating portion of each spring being of greater length than the lever arm at the rear end of said portion, yielding means interconnecting the seating portions of said springs to form a seat member, and supporting and tensioning means for said seat member secured to said frame, said supporting and tensioning means including pivotally supported upwardly and outwardly inclined supporting and tensioning members having their free ends secured to said seat member and adapted to move in a plane rectangularly related to the seating portions of the springs of said seat member for tensioning same at a right angle with respect to the longitudinal axes of the seating portions of said springs, when said seat member is forced downwardly toward said frame by a load placed on said seat member.

MORRIS F'REUND. 

